Electrodeposition of nickel



- United States Patent ELECTRODEPOSITION OF NICKEL Donald H. Becking,Birmingham, and Henry Brown, Huntington Woods, Mich., assignors to TheUdylite Research Corporation, Detroit, Mich., a corporation of MichiganNo Drawing. Application September 13, 1957 Serial No. 683,721

Claims. (Cl. 204-49) This invention relates to the electrodeposition ofnickel and more particularly it relates to the electrodeposition ofbright ductile nickel from aqueous acidic nickel electroplating baths.

In accordance with this invention, it has been found that certain vinylsubstituted m-dioxane compounds, such as those illustrated in Table I,containing the O. CHFCH-Cfi grouping I when used in very smallconcentrations in aqueous acidic nickel baths in conjunction with thewell-known organic sulfon-compounds (as illustrated in Table II) makepossible the production of brilliant ductile nickel plate.

While numerous unsaturated compounds have been used in the art inconjunction with sulfon-compounds to obtain bright ductile nickel plate,the number of highly satisfactory unsaturated vinyl substitutedcompounds have been very few. For example, 2-vinyl pyridine is actuallyfar inferior to pyridine as a nickel brightener when used in conjunctionwith an aryl sulfoncompound and vinyl benzene is insoluble in aWatts-type nickel bath.

The vinyl substituted saturated ring, m-dioxane, compounds of Table Igive far superior brightening results than when the vinyl group isattached to an aromatictype ring such as benzene or pyridine. This isthought to be due to the fact that in the compounds of Table I the vinylgroup is, in fact, an allylic group with the terminal, i. e. farthestfrom thedouble bond carbon atom of the allylic group as part of thedioxane ring.

TABLE I..-Continued Optimum Oonc., Grams/liter CHz=CH-C CHOCHax' 0.01 to0.06

OCz

7. OCH2 CH2=CHC /CHOC2H5 0. 01 to 0.06

O-CHg 8. O C H: g CHz=OH-C\ CHO(C2H4O),.H 0.01 to 0.06

The compounds of Table I are efiective in very low concentrations, andwhen fast agitation is used (air or mechanical, or hydraulic),concentrations as low as about two or three milligrams per liter showbeneficial brightening effects. In general, however, concentrations ofabout 0.01 to 0.06 gram/liter are preferred, though much higherconcentrations can be used, for example, up to about 0.2 gram/liter andin some cases as high as 0.5 gram/liter.

TABLE II Optimum Sulfur-Containing Brighteners Cone, grams/ liter 1.Benzene sulfonamide 0.1-3 2. Toluene sulionamides (oand p-) 0. 1-2 3.o-Benzoyl sulfimide 0. 1-2 4. N-Benzoyl benzene sultonimide. 0.1-1 5.p-Toluene sultonchloramide. 0. 1-1 6. p-Brom benzene sulonamide 0. 1-17. G-Chlor o-benzoyl sulfirnide. 0, 1-1 8. m-Aldebydo benzene snlfonami0.1-1 9. Sulfomethyl benzene sulfonamide 0, 1-6 10. Benzene sultonamidem-carboxylic 0. 1-3 11. 7-Aldehydo o-benzoyl sulfilnide 0.1-3 12.N-acetyl benzene sulfonimide. 0.1-2 18. Methoxy benzene sulionamides0.1-1 14. Hydroxymethyl benzene sulf0namide 0. 1-2 15. Allyl sulfonamide0. 4-12 16. Benzene sulionie acids (mono-, di-, and tri 1-15 17. p-Brombenzene sulfonic acid 3-6 18. Benzaldehyde sultonie acids (0, m, p) 2-619. Diphenyl sulfone sulfonic acid 1-8 20. Naphthalene sulfonic acids(mono-, di-, and tr) 1-8 21. Benzene snliohydroxamic acid 1-5 22.p-Chlor benzene sultonic acid- 1-15 23. Diphenyl sulfonic acid 1-5 24.m-Diphenyl benzene sulfonic acid. 1-4 25. 2-0hloro-5-sulfobenzaldehyde1-5 26. m-Benzene disulfonamide. 0. 5-1 27. Ally] sulionic acid 0. 4-1228. DichlOrOb'enzene sulfonic a 0. 5-8 29. Di-benzene sulfonimide- 0.1-3 30. Di-toluene sulf0nimide 0.1-3 31. Z-Butyne- 1,4-disulionie acid.5-20 32. 4-Hydr0xy-2-butyne-1-su1fonic acid 0.2-2 33.z-Butyne-i-sultonic acid 0. 05-1. 5 34. 3Cl1lor0-2-pr0pyne-1-sulf0nicacid. 0. 05-1. 5 35. 2-butene-1A-disulfonic acid .03-5 36. 2-cl1l0robutene-4-su1fonic acid- 0. 3-5 37. 2-cl1l0ro propene sulfonic acid0.1-1. 5 38. Cinnamyl sulionic acid; 0. 1-3. 0 39.3-Phenyl-2-propyne-1-sulf0nic acid. 0.3-3.0 40.4-Methoxy-2-butyne-1-sult0nic acid 0.2-2

The combination of the compounds of Table I with those of Table II canbe used in all types of acidic nickel baths that give good ductile graynickel deposits without the additives, such as Watts nickel baths, highchloride,

fluoborate, and sulfamate baths and mixtures of these various nickelsalts. Sodium, potassium, and lithium ions may be present, also ammoniumions, though the latter should preferably be kept below about 7 gramsper liter for maximum ductility and brightness. Boric acid is thepreferred buffer.

The best pH range is from about 2.8 to 4.5, though pH values of 2 to 6may be used. The temperature of' 3 the bath may be from room to 190 F.,though in general 120 F.l60 F. is preferred.

When no air agitation or strong mechanical or hydraulic agitation isused, it is preferred to use a suitable surface-active agent such assodium lauryl sulfate, sodium Z-ethyl hexyl sulfate or sulfonate, octylsulfonic acid, etc., to prevent gas-pitting. With air agitation, it isusually not necessary to use a surface-active agent but if desired,sodium 2-ethyl sulfate can be used which does not foam excessively, orotherwise a more powerful surface-active agent such as sodium laurylsulfate can be used in conjunction with an anti-foam such as a siliconeoil or a tallow alcohol.

The compounds of Table II can be used in amounts between about 0.1gram/liter and saturation and the preferred organic sultan-compounds tobe used with the compounds of Table I are the benzene sulfonamides andsulfonimides (0.1 gram/liter to saturation) especially when used inconjunction with allyl sulfonic acid (0.6-2 grams/liter) or Z-butynedisulfonic acid (3-10 grams/ liter). The preferred compound of Table Iis Example 2, which is 3,9-divinyl spirobi (m-dioxane), in aconcentration of 0.01 to 0.05 gram/liter.

The baths containing compounds of Table I and Table II are not verysensitive to giving poor adhesion due to broken electrical contacts orto small excesses of these compounds, and therefore these compounds donot readily cause double or laminated plates. For these reasons, thecompounds of Table I in conjunction with those of Table II giveexcellent results in bulk, tumble or barrel plating, as well as in therack plating of steel, zinc diecast, aluminum and brass articles.Especially superior results (brightness and ductility) are obtained withrapid agitation (air agitation or hydraulic agitation).

In the following examples typical bath compositions and conditions areillustrated for obtaining the bright nickel deposits in accordance withthis invention, but it is to be understood that they are representativeonly, and that the compounds of Table I can be used in such bathcompositions with each compound or combinations of the compounds ofTable II or other organic sulfoncompounds similar to those of Table IIsuch as those carrying di-, tri-, or tetra-sulfonimide groups of phenyl,biphenyl, naphthyl, or mixed phenyl, biphenyl etc., di-, tri-, andtetra-sulfonimides, such as in the approximate proportions indicated inTable II. Furthermore, the conjunctive use of the compounds of Table Iwith the compounds of Table II does not greatly reduce the excellentproperties which are characteristic of all of the organicsulfon-compounds of Table II with respect to the low sensitivity ofnickel baths containing the latter organic sulfon-compounds to pooradhesion from broken electrical contacts or delayed electrical contactsor from reverse or anodic currents as in periodic current reversals, orin anodic activation of the nickel plate for re-plate. Delays of as longas one minute before electrical contact is made, or anodic currents foras long as one minute in many cases, do not cause poor adhesion. Zincions or cadmium ions can be present in most of the nickel baths,especially in high chloride baths, in concentrations of at least 0.05 to0.1 gram per liter and also not aifect the adhesion during delayedelectrical contacts or periodic current reversals. As a matter of fact,the zinc or cadmium present in the nickel plate causes a more shallowtype of corrosion pit to occur in the nickel when chromium plated andexposed to a corrosive atmosphere (for example the atmosphere inindustrial areas). The relative insensitivity of such baths to passivityfrom anodic current, makes possible the use of periodic current reversalin its sacrificial form which tends to promote leveling and to improvethe corrosion protection afiorded to the underlying metal. For

example, after the initial deposition of a thin nickel plate (0.1 to 0.2mil), a sacrificial periodic current reversal cycle of ten or moreseconds anodic current preferably at low anodic current (5 to 10amps/sq. ft.) with about 1 to 5 seconds cathodic current can be used forperiods of about 1 to 2 or more minutes and then the procedure repeateduntil the desired thickness of plate is obtained. The benzenesulfonamides and sulfonimides and o-benzoyl sulfimide together withsmall concentrations of the compounds of Table I represent preferredcombinations of the compounds of this invention for the periodic currentreversal treatments.

Example I NiSO .6H O "grams/liter" 200-300 NiCl .6H O do 30-80 H3803 d0N-aBF do 0-0.S Example 2 of Table I (3,9-divinyl spirobi (m-dioxane)grams/liter 0.01-0.04 Sodium allyl sulfonate do 0.6-2 Benbenesulfonamide do 1-2 o-Benzoyl sulfimide do 0-2 Temperature F 120-160 pH3.2-4.8

Example II NiCl .6H- O grarns/liter -200 -d0 H 30 do 30-50 Example 2 ofTable I (3,9-divinyl spirobi (m-dioxane) grams/liter- 0.01-0.04 Sodiumallyl sulfonate do 0.6-2 o-Benzoyl sulfimide do 1-2 Benzene sulfonamidedo 1-2 Temperature F -160 pH 3.2-4.8

Example III NiSO .6H O grams/liter 200-300 NiC1 .6H O do 30-100 H3B03..d0 Example I of Table I (vinyl-m-dioxane) grams/liter 0.01-0.05o-Benzoyl sulfimide do 0.1-2 Temperature F 120-160 pH 3.2-4.8

Example IV NiS0 .6H O grams/liter 200-300 NiCl .6H O do 30-80 H BO do30-50 NaBF o 0-0.5 Example 2 of Table I (3,9-divinyl spirobi (m-dioxane)grams/1iter 0.01-0.04 2-Butyne 1,4-disulfonic acid Na, K, or Ni salt)grams/liter- 3-10 Benzene sultonamide do 1-2 o-Benzoyl sulfimide do 0-2Temperature F 120-160 pH 3.2-4.8

The above baths gave brilliant ductile nickel deposits that wereremarkably adherent even when electrical contact was not instantly made.Exceptionally good results Were obtained with air agitation, especiallyin baths of Examples I, II and IV.

What is claimed is:

1. A bath for electrodepositing bright, ductile nickel plate whichcomprises an aqueous acidic solution containing at least one electrolyteselected from the group consisting of nickel sulfate, nickel chloride,nickel fluoborate and nickel sulfamate, and having dissolved thereinabout 0.1 gram/ liter to saturation of at least one organic sulfon-.compound selected from the class consisting of benzene, biphenyl andnaphthalene sulfonic acids, sulfonamides and sulfonimides and the mixedphenyl, biphenyl and naphthyl sulfonamides and the mono-, di-, tri-, andtetrasulfonimides thereof, and dibenzene sulfonimides and the halogen,methyl, and aldehydo derivatives of said sulfonic acids, sulfonamidesand sulfonimides, and beta unsaturated alkene and alkyne sulfonic acidshaving 4-2 carbon atoms, and about 0.002 to about 0.5 gram/ liter of acompound selected from the group consisting of vinyl substitutedm-dioxane, and di-vinyl substituted bi(m-dioxane), and derivativesthereof, in which derivatives the m-dioxane ring is substituted with aradical selected from the group consisting of chloro, bromo, hydroxy,methoxy, ethoxy and hydroxy-ethoxy radicals.

2. A bath in accordance with claim 1 wherein said vinyl substitutedm-dioxane compound is 3,9-divinyl spirobi (m-dioxane) and is present ina concentration in the bath of 0.005 to about 0.2 gram/liter.

3. A bath in accordance with claim 1 wherein the vinyl substitutedm-dioxane is 3-viny1' m-dioxane and is dissolved in the said nickel bathin a concentration of 0.005 to about 0.2 gram/ liter.

4. A bath in accordance with claim 1 wherein said organicsulfon-compound is allyl sulfonate.

5. A bath in accordance with claim 1 wherein said organicsulfon-compound is 2-butyne-1,4-disulfonate.

6. A method of electrodepositing bright, ductile nickel plate whichcomprises electrolyzing an aqueous acidic solution comprising at leastone nickel salt selected from the group consisting of nickel sulfate,nickel .chloride, nickel fluoborate and nickel sulfamate, said bathcontaining dissolved therein about 0.1 gram/liter to saturation of atleast one organic sulfon-compound selected from the group consisting ofbenzene, biphenyl and naphthalene sulfonic acids, sulfonamides andsulfonim-ides and the mixed phenyl, biphenyl and naphthyl sulfonamidesand the mono-, di-, tri-, and tetrasulfonimides thereof, and dibenzenesulfonimides and the halogen, methyl, and aldehydo derivatives of saidsulfonic acids, sulfonamides and sulfonimides, and beta unsaturatedalkene and alkyne sulfonic acids having 4-2 carbon atoms, and about0.002 to about 0.5 gram/ liter of a compound selected from the groupconsisting of vinyl substituted m-dioxane, and divinyl substitutedbi(m-dioxane), and derivatives thereof, in which derivatives them-dioxane ring is substituted with a radical selected from the groupconsisting of chloro, bromo, hydroxy, methoxy, ethoxy and hydroxy-ethoxyradicals.

7. A method in accordance with claim 6 wherein said vinyl Substitutedm-dioxane compound is 3,9-divinyl spirobi (m-dioxane) and is present ina concentration in the bath of 0.005 to about 0.2 gram/liter.

8. A method in accordance with claim 6 wherein the vinyl substitutedm-dioxane is 3-vinyl m-dioxane and is dissolved in the said nickel bathin a concentration of 0.005 to about 0.2 gram/liter.

9. A method in accordance with claim 6 wherein said organicsulfon-compound is allyl sulfonate.

10. A method in accordance with claim 6 wherein said organicsulfon-compound is Z-butyne-l,4-disulfonate.

No references cited.

1. A BATH FOR ELECTRODEPOSITING BRIGHT, DUCTILE NICKEL PLATE WHICHCOMPRISES AN AQUEOUS ACIDIC SOLUTION CONTAINING AT LEAST ONEELECTROCLYTE SELECTED FROM THE GROUP CONSISTING OF NICKEL SULFATE,NICKEL CHLORIDE, NICKEL FLUOBORATE AND NICKEL SULFAMATE, AND HAVINGDISSOLVED THEREIN ABOUT 0.1 GRAM/LITER TO SATURATION OF AT LEAST ONEORGANIC SULFONCOMPOUND SELECTED FROM THE CLASS CONSISTING OF BENZENE,BIPHENYL AND NAPHTHALENE SULFONIC ACIDS, SULFONOMIDES AND SULFONIMIDESAND THE MIXED PHENYL, BIPHENYL AND NAPHTHYL SULFONIMIDES AND THE MONO-,DI-, TRI, AND TETRASULFONIMIDES THEREOF, AND DIBENZENE SULFONIMIDES ANDTHE HALOGEN, MEYTHYL, AND ALDEHYDO DERIVATIVES OF SAID SULFONIC ACIDS,SULFONAMIDES AND SULFONIMIDES, AND BETA UNSATURATED ALKENE AND ALKYNESULFONIC ACIDS HAVING 4-2 CARBON ATOMS, AND ABOUT 0.002 TO ABOUT 0.5GRAM/ITER OF A COMPOUND SELECTED FROM THE GROUP CONSISTING OF VINYLSUBSTITUTED M-DIOXANE, AND D-VINYL SUBSTITUTED BI(M-DIOXANE), ANDDERIVATIVES THEREOF, IN WHICH DERIVATIVES THE M-DIOXANE RING ISSUBSTITUTED WITH A RADICAL SELECTED FROM THE GROUP CONSISTING OF CHLORO,BROMO, HYDROXY, METHOXY, ETHOXY AND HYDROXY-ETHOXY RADICALS.